Method of producing autostereo pictures

ABSTRACT

AN AUTOSTEREO PICTURE COMPOSED OF A PLURALITY OF SEPARATE PICTURE IMAGES SOME OF WHICH CONTAIN PARALLAX, THUS GIVING A STEREO ILLUSION TO THE COMBINED COMPOSITE PICTURE. COMBINATIONS MAY INCLUDE IMAGES APPEARING AT A POINT OF CONVERGENCE (N THE PLANE OF THE PICTURE, SUPPORT, OR FRAME), IN ADDITION TO OTHERS AT VARIOUS POSITIONS EITHER BEHIND OR IN FRONT OF THE POINT OF CONVERGENCE. THE FINAL PICTURE FORM MAY ALSO INCLUDE VARIOUS SPECIAL RELATIONSHIPS BETWEEN TWO AND THREE-DIMENSIONAL IMAGES, FOR EXAMPLE: (1) A TWO-DIMENSIONAL IN THE PLANE OF THE POINT OF CONVERGENCE AND A THREE-DIMENSIONAL APPEARING BEHIND THAT PLANE, AND (2) A THREE-DIMENSIONAL IN FRONT OF THE PLANE OF THE POINT OF CONVERGENCE, A THREE-DIMENSIONAL BEHIND THAT PLANE AND A TWO-DIMENSIONAL IN THAT PLANE. THE METHOD FOR THE PRODUCTION OF SUCH AUTOSTEREOGRAMS MAY INCLUDE THE CONVERSION OF AT LEAST ONE TWO-DIMENSIONAL PICTURE IMAGE INTO A LINEIFORM RECORD CONTAINING PARALLAX. THIS CAN BE ACOMPLISHED BY CORRECTLY FOCUSING SUCH A SUBJECT OR OBJECT IMAGE UPO THE PHOTOSENSITIVE LAYER OR FILM OF AN AUTOSTEREOGRAPHIC DEVICE AND THEREAFTER PROVIDING THE RELATIVE MOTIONS WITHIN THAT DEVICE AND WITH RESPECT TO THE OBJECT IMAGE. PICTURES THUS FORMED ARE THEN COMBINED WITH OTHERS OR COMBINATIONS OF OTHERS, EITHER SIMILAR IN CONSTRUCTION OR OF THE TWO-DIMENSIONAL TYPE, TO FORM A FINISHED AUTOSTEREOGRAPHIC PICTURE.

OCII. 3, 1972 w SALYER ET AL 3,695,878

METHOD OF PRODUCING AUTOSTEREO PICTURES Original Filed May 26, 1967 aSheets-Sheet 1 Oct. 3, 1.72 w. SALYER ETA!- 3,595,373

METHOD OF PRODUCING AUTOSTEREO PICTURES Original Filed May 26, 196755heets-Sheet 2 Oct. 3,1972 w.1 SALYER ETAL METHOD OF PRODUCINGAUTOSTERI'IO PICTURES 6 Sheets-Sheet 3 Original Filed May 26, 1967 FIG.4A

FIG.4

FIG. 4C

Oct. 3, 1972 w, SALYER ETAL 3,595,878

METHOD OF PRODUCING AUTOSTEREO PICTURES Original Filed lay 26, 1967 6Sheets-Sheet 4 42 Fl G. 5 FIG. 5A

Oct. 3, 1972 w. SALYER ETAL 3,595,373

METHQD OF PRODUCING AUTOSTEREO PICTURES Original Filed May 26, 1967 eSheets-Sheet 5 w. L. SALYER ETAL v 3,695,878 METHOD OF PRODUCINGAUTOSTEREO PICTURES Original Filed May 26; 1967 Oct. 3, 1972 6Sheets-Sheet 6 G L. w

. F L owzwhw muuwiaom W United States Patent Patent No. 3,520,588.Divided and this application Apr. 22, 1970, Ser. No. 38,630

Int. Cl. G03c 9/00 US. Cl. 9640 10 Claims ABSTRACT OF THE DISCLOSURE Anautostereo picture composed of a plurality of separate picture imagessome of which contain parallax, thus giving a stereo illusion to thecombined composite picture. Combinations may include images appearing ata point of convergence (in the plane of the picture, support, or frame),in addition to others at various positions either behind or in front ofthe point of convergence. The final picture form may also includevarious special relationships between two and three-dimensional images,for example: 1) a two-dimensional in the plane of the point ofconvergence and a three-dimensional appearing behind that plane, and (2)a three-dimensional in front of the plane of the point of convergence, athree-dimensional behind that plane and a two-dimensional in that plane.

The method for the production of such autostcreograms may include theconversion of at least one two-dimensional picture image into alineiform record containing parallax. This can be accomplished bycorrectly focusing such a subject or object image upon thephotosensitive layer or film of an autostereographic device andthereafter providing the relative motions within that device and withrespect to the object image. Pictures thus formed are then combined withothers or combinations of others, either similar in construction or ofthe two-dimensional type, to form a finished autostereographic picture.

This application is a division of US. Ser. No. 641,554, filed May 26,1967, now US. Pat. No. 3,520,588.

This invention primarily relates to the production of autostereographicpictures, including the reproduction and combination of severaltwo-dimensional and/or three-dimensional prints or transparencies toform a single composite picture.

Autostereography has long been the subject of study, experimentation,and frustration. Since the early 1900s inventors have contributed ideasrelated to theories of the stereomechanism and to equipment, and methodsfor reproducing images in such a way as to culminate in athreedimensional picture. Numerous problems have been attendant withthese developments, and still today commercial fruition eludes producersbecause of those remaining.

As those who are knowledgeable in the art know, cameras suitable for usein the production of three-dimensional pictures are of considerable sizeand weight, and in order to produce the necessary lineiform image,require a combination of precise, accurate movements during the timeexposure of the photosensitive layer or film. Thus, until now it hasbeen necessary to limit autostereographic pictures to still life eitherposed in a studio or photographed, at considerable expense andinconvenience, on location.

It, therefore, is an objective of the invention to overcome theselimitations so that it is now possible to reproduce still life subjectsinto autostereo pictures without the necessity of on locationphotography with an autostereographic camera.

Additionally, it is an objective of the invention to make possible thereproduction and use of action subjects in autostereographic pictures.

More particularly, the invention represents the discovery anddevelopment of a method of reproducing and converting two-dimensionalpicture's, transparencies, or the like, into autostereograms. In sodoing it is necessary to rephotograph the existing two-dimensionalpicture using the three-dimensional technique of combined relativemotions between the object image and the photographic film.Additionally, applicants have invented a method of combining two andthree-dimensional pictures, or combinations thereof, in such a manner asto give improved clarity and illusion of depth.

Based upon these new techniques it is obvious that considerableadvantages have been attained. It is now possible to photograph anyobject or scene with typical still or motion picture camera equipmentand subsequently reproduce the resultant pictures in autostereo form,thus eliminating costly on location autostereognaphic camera use andvastly broadening the topical coverage possible for use in the finalpicture form.

These and additional objectives and advantages of the invention willbecome more apparent upon reference to the following description, claimsand appended drawings wherein:

FIG. 1 schematically illustrates an observer viewing a printincorporating the present invention;

'FIG. 2 is a schematic illustration of the principle of such viewing;

FIG. 3 is a schematic diagram illustrating parallax and showing thevalues determinative thereof;

FIG. 4 is a schematic diagram indicating how a typical autostereographiccamera is traversed around a two-dimensional picture forming the objectimage;

FIG. 4A is identical to FIG. 4 except that the object image has beenskewed with respect to the plane of the point of convergence;

FIG. 4B shows an alternative arrangement for positioning the subjectimage or object;

FIG. 4C is another position in which the subject or object image may bemounted;

FIG. 5 is a schematic diagram illustrating another autostereographicpicture taking technique in which the camera is fixed and the objectimage is traversed with respect thereto;

FIG. 5A is another schematic diagram showing two two-dimensionalpictures being mounted for simultaneous reproduction with an arrangementsimilar to that shown in FIG. 5;

FIG. 6 is a schematic diagram showing a masking technique which may beused in the FIGS. 4 and 5 arrangements to produce a single autostereonegative;

FIG. 7 is another view of the FIG. 5A arrangement for making pictures ofthe type described;

FIG. 8 is a schematic flow diagram illustrating the procedures attendantto the combination photographs in the production of a compositeautostereogram; and

FIG. 9 depicts schematically the technique necessary in the productionof a mask which is used in the FIG. 8 method.

Throughout the specification reference will be made to planes. All arepositioned relative to a horizontal plane passing through both eyes ofan observer or the camera lens disregarding how the head or camera istilted. A picture being viewed, when properly held, is in a. verticalplane more or less orthogonal to the line of sight in the horizontalplane and the picture planes hereinafter referred to are parallel withthe vertical plane so described unless otherwise designated.

With continuing reference to the accompanying dra'wings wherein likereference numerals designate similar ice parts throughout the variousviews, and with initial attention directed to FIG. 1, reference numeral2 is used to designate a picture of the invention. In FIG. 1, anobserver is viewing a picture made up of two complementary areas 13 and14 which together make the full picture. The lines of sight to the leftand right eyes are respectively indicated by broken lines 11 and 12.That is, the left eye is observing a point 21 of the image and the righteye is observing the point 22 of the image in the area 13. These points21 and 22 may be images of the same part of an original two-dimensionalpicture and appear to merge at the point 23 in the plane 24 behind theplane of the point of convergence, that being support 15. The backgroundand foreground image areas 13 and 14 may be of any scene desired and maybe made from or composed of two-dimensional pictures in which thereproduced binocular differences include a small degree of parallax aswill hereinafter be discussed. The picture 2 is not limited to only twocomplementary areas but may include more if desired.

A further illustration of the principle is shown in FIG. 2. The point 30of the picture contains both the right and left eye views of image area14 which in this case is a two-dimensional undivided picture. The imagearea 13 appears to lie in plane 24 behind the plane of the point ofconvergence this being the plane of frame 5 in which area 14 lies.

A lenticulated viewing screen 4 covers both image areas 13 and 14, andis, of course, aligned with the lineiform elements 7 of area 13. Apicture according to the present invention has a number of interestingattributes. There is the depth effect in the picture area 13 because itappears to be floating at the plane 24 behind the plane of the point ofconvergence.

A two-dimensional picture is made to appear floating in space away from,either in front of or behind the plane of the point of convergence,usually the plane of the support on which it is printed. This floatingpermits the monocular clues of depth to have a much greater effect.Monocular clues are evidenced by the fact that a near object hides amore distant one, that near objects appear larger, parallel lines appearto converge in the distance, and that distant objects appear more hazyand to have less contrast. Also the shape and placement of shadowsenhance depth effects. The mechanism which gives the picture thefloating" appearance away from its actual surface, is further enhancedby deemphasizing the reference points which make a two-dimensionalpicture appear flat while emphasizing these monocular clues of depth.

The present invention further emphasizes this effect by the very factthat there is another picture, namely area 14, in a stereo relationshipto the image area 13. This in turn greatly enhances the monocular cluesto depth in the area 13. Most observers will not even notice that thewhole picture 2 was not taken autostereographically. Instead either orboth of the areas 13 and 14 may be composed of pictures made originallywith an ordinary relatively inexpensive camera. A second, quiteunexpected, effect is a reversal reaction from the background area 13 tothe foreground area 14 tending to reduce the cardboard effect of thatarea. To most observers, even the two-dimensional picture area 14 in theplane of the support, appears to be rounded and to have depth. That is,the monocular clues such as the placement of shadows give a roundness toarea 14 when it is associated with the floating background 13. Theoverall effect is quite astounding and attractive.

Autostereographic cameras of traditional design have fixed limits oflens traverse. As the lens to subject distance becomes great, the powerof the camera to differentiate between distant points becomes less andfinally approaches zero. This is particularly true for scenic exposures.

This relationship is illustrated by FIG. 3 of the drawings and in TableI below. Table I values are predicated upon an autostereographic camera'whose maximum lens traverse is 1 /2 feet using a 12 inch lens set atinfinity. The parallax created in a scenic picture taken under theseconditions can be calculated using the formula:

S =e f(1/d --l/d where:

S =para1lax difference of point x with respect to point 0.

c =camera lens traverse (1% feet).

f=lens focal length (1 ft. at infinity).

d =distance of the point of convergence (point 0) from the camera lens.

d distance of the image object (point x) from the camera lens.

This formula and its derivation can be found discussed in an article TheShape of Stereoscopic Images by John T. Rule, appearing in the Journalof the Optical Society of America; vol. 31: pages 124l29, 1941.

In each case point 0 is about 10% closer to the lens than point x. Up toabout 20 to 30 feet the camera, a typical autostereognaphic camera,creates enough parallax on point x to distinguish its position frompoint 0. Beyond 30 feet, however, the power to discriminate willdiminish until, for all practical purposes, points 0 and x appear to bein the same plane.

Since the power to discriminate between distant points is essentiallylost anyway, advantage of this fact can be taken to producethree-dimensional scenic pictures at a. low cost with resultspractically equivalent to those obtained when on locationautostereographic camera pictures are resolved.

FIGS. 4-5 illustrate several of the techniques useful in thereproduction of two-dimensional pictures into extended stereo-basepictures. Using these techniques requires only that the scene, sought tobe reproduced, be taken with an ordinary camera from which atransparency or print can be secured. With particular reference to FIG.4 it can be seen that the print or transparency 36, so secured, ismounted and ready to be rephotographed with the autostereographic camera30. The rephotography is accomplished in the conventional manner; thecamera 30 is traversed, as is shown by arrow 38, with the point ofconvergence 32 being either in front of or behind the subject plane 34.

FIG. 4A is another embodiment of this same technique wherein the print36 is mounted at an angle 'F with respect to the subject plane 34. Inthis case the picture area behind the plane 34 will appear to recedewhile that area in front of plane 34 will appear to protrude from theplane of the point of convergence in the three-dimensional reproduction.

The embodiments of FIGS. 4B and 4C simply show further modifications inwhich the two-dimensional subject is contorted to produce varied butsimilar effects. The technique is not intended to be limited to thoseembodiments alone since the subject picture could be bent and contortedinto numerous such configurations to produce like effects in the finalautostereo picture.

When using the above techniques in rephotographing two-dimensionalsubjects, the usual camera traverse will result in as much parallax onthe autostereo print as is desired or as can be resolved. To achieve anequivalent amount with an autostereographic camera on location wouldrequire a stereo base of such magnitude that it is impractical toconsider.

FIG. schematically illustrates another variation of the techniquediscussed in connection with FIG. 4. In this illustration the subjectprint is mounted on a turntable 43 for rotation as indicated by arrow39. The center of the camera 30 and its lens 40 remain fixed on a linethrough the axis of rotation of the turntable 38.

In accordance with the invention and as is shown in FIGS. 5A and 7, onesimple method of preparing extended stereo base pictures involvesmounting a cutout 31 of the picture which is to constitute theforeground area upon a sheet of glass 37. This picture is thenphysically mounted in front of a two-dimensional background picture 36.

The latter picture 36 may show a person running, or present any otherform of stopped motion as, for example, the birds therein depicted.

FIG. 7 schematically illustrates in combination a lens 40, taking screen41, and sensitive film 42, of a standard autostereo camera 30 whichtakes the exposure series. The camera in FIG. 7 including the takingscreen, is moved between exposures. The FIG. 5 illustration, as abovediscussed, shows the turntable 43 concept. In FIGS. 5A and 7, theturntable 43 is rotated about its vertical axis at lying in the plane ofthe point of convergence 32 in which the picture 31 is located. Thus,the ultimate lenticulated lineiform print made from these photographshas an image area of the picture 31 appearing in the plane of the pointof convergence and an image area of the picture 36 appearing below orbehind that of the picture support.

The foregoing represents only one method of producing combinedautostereo pictures of the invention from a plurality of two-dimensionalpictures.

Another similar method is depicted in FIG. 6. There theautostereographic camera 30 and lens 40, having a point of convergenceat 32, is traversed around the twodimensional picture subjects as isshown by arrow 38. Both pictures 36 and 31 are masked as at 33 and 35-respectively so that only the unmasked portion of each will be recordedon the image plane of the camera. Each of these masked pictures is, inturn, mounted in their dotted line position and the camera 30 istraversed to record the respective images. The camera traversal for eachexposure is in the same direction, and as is observable from FIG. 6. Thesubject pictures, in order to completely fill their images areas aremounted equal distances Y in front of and behind the plane of the pointof convergence. Such will also provide an equality of parallax on eachpicture with respect to the frame of the composite autostereo picture.If the camera traversal is reversed, a pseudostereo picture will result.

Another, and presently the preferred, method useful in the production ofcomposite autostereo pictures is schematically shown in FIGS. 8 and 9.This technique combines two or more pictures into one by surprinting.The picture forms capable of being so combined, of course, may be eithertwo or three-dimensional in nature. The following table, Table II,illustrates the possible combinations of three pictures.

Picture Number NOTE.-O point=the frame position (two-dimensional pointof con- Velgence); +=in (rout of the frame; ++=in extreme front 0! theframe; =behind the trame; --=in extreme depth in the frame.

As those skilled in the art will appreciate, any and all of theautostereo pictures produced by this method will require a means ofresolution, similar to the viewing screen 4 shown in FIG. 2. Resolutionis most normally acquired through the use of lenticulated viewingscreens which when properly aligned with the lineiform picture imageproduction of the autostereo camera will, in combination with otherstereomechanisms, produce the proper right and left eye images. Thesehave a high optical efficiency and commonly have between 16 and 400lenticules per horizontal inch, the number of which is equal to thenumber of lineiform images appearing on the picture.

The combined pictures, representing the picture of the invention, mustregister under each lenticule and have common centers at the lenticule.

Now, with particular reference to FIG. 8, the steps followed in thepractice of the method of the invention are schematically outlined forthe combination of two transparencies A and B. If both arethree-dimensional type transparencies, it is necessary that a grid berecorded along the edge of each during their production. One suitableway to accomplish this is fully explained in the Huifaker et al.copending US. patent application Ser. No. 465,491, filed June 21, 1965,now US. Pat. No. 3,420,663. Of course, any of the uniform and undividedtwo-dimensional transparencies (non-lineiform) need not be so treated.The introduction of this grid assures ease in the proper alignment ofthe transparencies, resulting in a constant relationship to the ultimateviewing axis.

Transparency A, which is to be surprinted, is placed over transparency Bin the chosen position. Since the grid portions of each will overlap thetwo can be adjusted until exact parallelism and lineiform lineoverlapping is achieved. This insures that the viewing position of bothmatch perfectly. After positioning, the transparencies are permanentlypunched for a pin register system. All continuous tone separations,masks, and screen positives are similarly key punched to assure properregistration throughout.

The transparencies A and B are again separated after punching and eachis subjected to a typical and well known color/separation process, whereeach is transformed into its component continuous tone separationnegatives (Cyan, Magenta, Yellow, and Black). These are, in turn,reduced to original half-tone screen positives and then first duplicatehalf-tone screen positives.

From the continuous tone separation negatives of either transparency A"or B, (A" being selected for purposes of illustration in this case), thebest suitable for contact printing is selected. This separation, or thetransparency itself, if none of the negatives are suitable, is then usedto make a positive mask 48 (FIGS. 8 and 9) of the portion of area ofpicture A that is to be surprinted. The mask is made by contact printingeither directly or indirectly on a high contrast film, depending uponwhether a negative or transparency is used. If necessary, opaqueing isadded around the clear positive area of the mask to make certain thatonly the proper portion will ultimately be printed.

A negative mask 52 also is obviously required and may be convenientlymade from the prepared positive mask 48 as is illustrated in FIG. 9. Thepositive mask 48 is laid over another piece of high contrast film 52between which is located a clear spacer 50 of approximately 0.020 inchthickness. Thereafter film 52 is exposed by a light source 54. Thespacer 50 causes the resulting negative mask 52 to be slightly largerthan positive mask 48. This difference in mask size assures the properfilling of each area of the composite autostereo picture, there being acomplete exposure without lapping at the area intersections.

As is well known in photographic color separation work, that preparatoryto printing, screen positives are duplicated twice to ensure dothardness. Preferably, but not necessarily, during this secondduplication A and B pictures are surprinted. It is also possible toaccomplish this during the first duplication. FIG. 8 follows the cyan"separation of pictures A and B to a final surprinted second duplicatehalf-tone screen positive 56.

However, in order to complete the process each of the other separationsmust also be similarly treated. These second duplicates 56 areultimately used to produce the printing plates used in a typical fourcolor printing process of the final autostereo pictures of thisinvention.

For surprinting, the first duplicate cyan half-tone screen positive 60of A" picture is placed in contact with duplicating film 58 and thepositive mask 48 is placed over both. This combination is then exposedby a light source 64 resulting in the exposure of only area 70 upon film58. The area 70, of course, represents the area of picture A which is toappear in the autostereo picture of the invention. After exposure the Ascreen positive and positive mask are removed and the first duplicatecyan half-tone screen positive of picture B is placed in contact withthe same piece of film 58. Now the negative mask 52 of picture A isplaced over both and light source 66 completes the exposure of film 58in areas 72; this total exposure of film 58 results in a compositesecond duplicate half-tone screen positive 56.

The final autostereo pictures, subsequently printed by plates producedfrom these composite second duplicate half-tone screen positives 56, mayresult in any of the planar combinations aforementioned in Table H.

The techniques of this invention obviously represent advances over theprior art methods and pictures, and by their introduction expressesincurred in the production of autostereo pictures will be considerablyreduced. In addition, it is now possible to have an almost unlimitedtopical coverage in autostereo pictures thus providing additional areasfor marketability.

The invention may be embodied in other specific forms without departingfrom the spirit of the essential characteristics thereof. The presentembodiments are therefore to be considered in all respects asillustrative and not restrictive, the scope of the invention beingdictated by the appended claims rather than by the foregoingdescription, and all changes which come within the meaning and range ofthe claims are therefore intended to be embraced therein.

We claim:

1. A method of producing an autostereo picture including the steps ofoverlaying, aligning, and indexing at least two information carryingtransparencies, at least one of which is lineiform in nature; separatingthe said transparencies and from each producing in succession continuoustone separation negatives, original half-tone screen positives, andfirst duplicate half-tone screen positives; selecting the choicenegative of at least one of the pictures and contacting said selectednegative with a first sheet of high contrast film; exposing saidcontacted elements to produce a positive mask for each selected picturenegative; spacing said positive mask from a second sheet of highcontrast film and exposing these to produce a negative mask for eachpicture, these being slightly larger than the positives; successivelyoverlaying, exposing, and removing from a photosensitive duplicatinglayer the first duplicate half-tone screen positive for each of saidselected pictures, and the corresponding positive masks thereof; againoverlaying and exposing said layer this time with the first duplicatehalf-tone screen positive for each of the unselected pictures, and therespective negative masks to thereby produce a composite secondduplicate half-tone screen positive of said transparencies; processingsaid second duplicates to a record at least part of which is lineiformin nature; making copies of said record; and

combining said copies each with and in register behind a viewing means.

2. The method according to claim 1 wherein the spacing of said positivemask is about 0.020 inch from said high contrast film.

3. A method of producing an autostereo picture including the steps ofaligning and indexing a plurality of information bearing transparencieshaving a plurality of colors; at least one of which has lineiform imagesthereon; color separating the individual transparencies; making positiveand negative masks from at least one color separation negative; insuccession and during the color separation, masking the respectiveseparation positives so as to record the complementary areas of eachupon a single photosensitive layer; processing the color separationpositives to a record, at least part of which is lineiform in nature;making copies of said record; and combining said copies each with and inregister behind a viewing means.

4. The method according to claim 3 wherein the negative mask is made byspacing the positive mask approximately 0.020 inch from a sheet of highcontrast film; and exposing the combination to a light source.

5. The method according to claim 3 wherein the masking steps areperformed to produce a series of second duplicate halftone screenpositives.

6. A method of producing an autostereo picture comprising the steps of(a) displaying a plurality of subject elements, at least one of which istwo-dimensional in nature in photographing position relative to acamera, the camera and at least one of said subject elements beingspaced from a reference point;

(b) successively exposing different lines of a photosensitive layerthrough a taking screen to said subject elements while simultaneouslycausing relative movement between said camera and at least one of saidsubject elements, at least one of said camera and subject elementsmoving along the arc of a circle having said reference point as itscenter;

(c) processing said layer to a lineiform record;

(d) making copies of said record; and

(e) combining said copies each with and in register behind a viewingmeans.

7. The method of claim 6 in which each of said subject elements is atwo-dimensional reproduction.

8. The method of claim 6 in which one of said subject elements is at thepoint of convergence.

9. The method of claim 6 wherein portions of the subject elements arefirst masked to provide a plurality of complementary subject areas, andthereafter the subject elements are successively displayed for exposureto the photosensitive layer.

10. The method according to claim 6 wherein said subject elements aredisplayed concurrently.

References Cited UNITED STATES PATENTS 1,942,638 1/1934 Draper 96-40 UX1,862,847 6/ 1932 Draper 96-40 X 2,785,976 3/ 1957 Ogle 9640 X 3,232,2022/1966 Rice 96-40 X DAVID KLEIN, Primary Examiner U.S. Cl. X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,695,878 Dated October 3, 1972 lnventofls) Walter L. Salver, et al.

It is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

Column 1, line 5, after "37662" insert assignor to Eastman KodakCompany, Rochester, N.Y. a Corporation of New Jersey Signed and sealedthis 26th day of February 19714..

(SEAL) Attest: v

EDWARD M.FLETCHER,JR. MARSHALL DANN Attesting fficer Commissioner ofPatents FORM PO- 'l050 (10-69) uscoMM-Dc 60376-P69 UNITED STATES PATENTOFFICE CERTIFICATE OF CORRECTION Patent No. 3,635,878 Dated October 3,1972 Inventor Walter L. Salver. et :11.

It is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

Column 1, line 5, after "37662" insert assignor' to Eastman KodakCompany, Rochester, N.Y. a Corporation of New Jersey-.

Signed and sealed this 26th day of February l97) (SEAL) Attest: u

EDWARD M.FLETCHER,JR. c, MARSHALL DANN Attesting Officer" commisslonerof Patents 1 FORM PO- IO50 (10-69) uscoMM-oc 60376-P69

